Photos - many of them aerial images - Walter Mittelholzer took both in Switzerland and during his adventurous flights to places like Spitzbergen (1923), Persia (1924/25), across the entire African continent to Cape Town or across Mount Kilimanjaro (1930).
The Walter Mittelholzer collection of the ETH Library Image Archive comprises more than 18'000 photographs. A large selection of the Images from Mittelholzer's flights abroad are available on Wikimedia Commons. Alternatively an API access to the entire Mittelholzer collection available on E-Pics Image Archive Online can be granted upon request.